Refactor themePatternPhase and tab_view in preparation for fixing crbug.com/176857

- Swap themePatternPhase to themePatternPhaseForAlignment with an arg to indicate whether the image should be aligned with the window frame or the tab strip.
This is needed in order to split IDR_THEME_TAB_BACKGROUND into two images in https://codereview.chromium.org/18486007/
and to make themes like http://www.corp.google.com/~pkotwicz/theme_testing/tab_background_tinted_frame.crx line up properly on mac (Which is also fixed in https://codereview.chromium.org/18486007/).
- Move drawing the fill for the active tab to drawFillForActiveTab from drawFill in tab_view.mm. This is in preparation for https://codereview.chromium.org/18486007/ which makes painting the inactive tab more complex.

BUG=176857
TEST=None

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=212721

[pkotwicz, 2013-07-17 21:24:00]

Nico, can you please take a look?
I moved some of the refactoring in https://codereview.chromium.org/18486007/ to
a separate CL as you requested.

This CL does not make use of THEME_PATTERN_ALIGN_WITH_FRAME.
https://codereview.chromium.org/18486007/ will make use of it.
framed_browser_window.mm should probably use THEME_PATTERN_ALIGN_WITH_FRAME
instead of using its own constant.

The use of THEME_PATTERN_ALIGN_WITH_FRAME also allows themes such as
http://www.corp.google.com/~pkotwicz/theme_testing/tab_background_tinted_fram...
to be properly aligned on mac (which https://codereview.chromium.org/18486007/
fixes for free)

https://codereview.chromium.org/19576007/diff/2001/chrome/browser/ui/cocoa/ta...
File chrome/browser/ui/cocoa/tabs/tab_view.mm (left):

https://codereview.chromium.org/19576007/diff/2001/chrome/browser/ui/cocoa/ta...
chrome/browser/ui/cocoa/tabs/tab_view.mm:360: // highlight is drawn using the
foreground tab bitmap.
> This was called for non-selected tabs with alpha > 0 previously,
> and now isn't. Is that intentional?

[self drawFillForActiveTab:dirtyRect] is used to draw the highlight.

The main reason I decided to do this refactoring is that 
https://codereview.chromium.org/19115003/ splits IDR_THEME_TAB_BACKGROUND into
two images IDR_THEME_TAB_BACKGROUND and IDR_THEME_TAB_BACKGROUND_OVERLAY. That
changes makes drawFill deal with two "overlay" images. (So I felt compelled to
try to make things hopefully a bit more straightforward)

[pkotwicz, 2013-07-18 19:48:40]

Ping?

[Nico, 2013-07-18 19:52:56]

Whoops! Looking now sorry.

CL description: "Refactor X" is an ok title, but the description should mention
what you did (this is an example of a good CL description:
https://codereview.chromium.org/18967002/ ). For pure refactorings, saying "no
intended functionality change" or similar in the CL description is useful too.

[Nico, 2013-07-18 19:58:30]

lgtm, nice!

https://codereview.chromium.org/19576007/diff/2001/chrome/browser/ui/cocoa/ta...
File chrome/browser/ui/cocoa/tabs/tab_view.mm (left):

https://codereview.chromium.org/19576007/diff/2001/chrome/browser/ui/cocoa/ta...
chrome/browser/ui/cocoa/tabs/tab_view.mm:319: bool selected = [self state];
nit: Keeping the bool is imo better for readability, even if it's used only
once.

https://codereview.chromium.org/19576007/diff/2001/chrome/browser/ui/cocoa/ta...
File chrome/browser/ui/cocoa/tabs/tab_view.mm (right):

https://codereview.chromium.org/19576007/diff/2001/chrome/browser/ui/cocoa/ta...
chrome/browser/ui/cocoa/tabs/tab_view.mm:327: bool usingDefaultTheme =
themeProvider && themeProvider->UsingDefaultTheme();
Why did this move up? It's not used until before where it was previously afaict.

[Nico, 2013-07-18 19:58:41]

(with better CL description)

[commit-bot: I haz the power, 2013-07-19 19:12:08]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/19576007/13001

[commit-bot: I haz the power, 2013-07-19 19:23:26]

Step "update" is always a major failure.
Look at the try server FAQ for more details.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2013-07-19 19:36:18]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/19576007/13001

[commit-bot: I haz the power, 2013-07-20 02:09:22]

Change committed as 212721